Shock absorber device



- July 12, 1932. F H ROYCE 1,866,671

SHOCK ABsoRBBR DEVICE Filed June A24. 1927 2 5119315.55661 1 l gru-nto@akamu July 12, 1932.

F, H. 'ROYCE SHOCK ABSORBER DEVICE 2 Sheets-Sheet 2 Filed June 24'. 1927(gn/60,11%@ en/er1 'a6 Hayg @51, j

ttomag Patented July 12, 1932 srCNoR To noLLs ROYCE LIMITED, CE1-DERBY,ENGLAND FREDERICK HENRY ROYCE, oEfWEsfr WITT'EEING, NEAR CHICESTER,ENGLANnAs- SHOCK ABSORBER ADEVTCE Application filed .Tune 24, 1927,Serial No. 201,183, and in Great Britain .Tune 24, 1926.

AThis invention relates to shock absorbers and more particularly tohydraulic shock absorbers, in which a piston divides a cylinder into twocompression chambers, with spring controlled ley-passes for thecontained liquid. Y

' The chief object of the invention isto provide means by which smallmovements of the springs of a vehicle are resisted only slighty, whileduring flexing of greater amplitude the resistance builds up rapidly,reaching a maximum value, then continues constant through any furtherflexing of the springs.

Another object is to provide for this ac'- tionV in both directions ofmovement, but with greater resistance to movement in one direction thanin the other. e

' Another object is to provide a mechanism which will operate in theset'wo desirable ways, almost independently of changes of viscosity of thecontained liquid, due to changes of season and temperature.

Other objects will be seen in-the structure,

as described below and shown in the accom-V Vof same, with some parts intop view.

Fig. 3 shows in section the end (Z4 ofthe Ypiston with its by-pass slotse6, the piston valve e1 being seen in end view in the direction of arrow3 in Fig. 2; and

Fig. 4 is a vertical transversesection on line 4--4 of Fig. 1. Y

The same reference characters refer to corresponding parts in thediierent iigures.

The body casting a comprises the cylinder a0; the chamber a1 above thecylinder; the rocker arm housing a2 in Vcommunication with chamber a1;the laterally extending boss a3, Fig. 4 providing a bearing for therocker shaft b; the reservoir a4, Fig. 4, in communication with chambera1 and extending down one side of the casting to communicate withpassage a9, Fig. 1, by means of holes a14 and L15 in the hollow plug a7,Figs. 1 and 4. `,The cap a5 secured to the end of the structureand capa6 secured over the rocker arm housing form a closedsystem to be filledwith `a liquid, preferably. oil. The only break of the closed system isdueto shaft ZJ, which connects with'lever b1 on the outside. Leakagethrough the bearing of shaft b is prevented by a suitable pac ing glandin housing b2, Fig. 4.

Lever b1 is to .befconnect-ed by suitable means to an axle ofa vehicle,while the body casting@ is mounted on some part of the vehicle body, tooppose resistance to movements of the aXle in the'manner describedbelow.'` l 'K k f' The inner end ofshaft bis squared,as at b5, Fig.1,arid has rockerarm o6 `clamped* to it vby bolt o7. Thev rocker armdepends through opening L13 in the cylinder wall and opening o16'Y inthe piston walland ,is connected by link bS to knuckle b9, which ismounted in the head @Z1 of piston cl. VBy means of this train, anyrelative movement of vehicle body andaxle will move piston d in cylindera0. v v d v In addition to head d1, the piston has a diaphragm cl2. Thepiston thendivides the cylinder into two compressionchambers at its twoends and if the head and diaphragm Y were solid and thesy'stemlilledwith oil, the piston would be prevented, from moving.

lThe objects of the invention, stated above,

are attained Vby valve controlled ports formed in the pistonthroughwhich the two Compression chamberscommunicate. v

As seen in Figures 2 and 4, ports 613 Y are formed in suitable bosses inthe piston casting and vconnect the compressionl chamber beyond head d1on the left with that beyond diaphragmA Z2 on the right, whilepreventing communicationV of either-chamber with the open central partofthe piston and the rocker V.the `close fitting pistonv valve el." Thebore vis l broken into three faces by the two `annular grooves 612 andvalve e1 is shown registering with `the middle lface, being normallyheld in so j in perfect alignment.

predetermined distance from normal vposi- :t'he'machin-ing-ouuofslotseiand e7.

'\ of -the 'pistonican occur in eitherI direction1 Without passage; ofloilfrom one compression 'ments' are 'smalhdueto' ordinary -unevennessthe middle-face o'ffth'e jbore, springs *eat and ell' yielding easily.

"increasing 'resistance f does `not'continue-be- Within guide" e2the-spring *ell'surrounds stud e5, which is mounted on diaphragm cl2,the spring bearing against nut e8 at one end and against spacer:ring-e9- in theguideatfits 3 other end and so tends to move Valve e1 tothe leftgagainstspring e4. The-two springs are' made otsuchglength andspacer rings e3 .'a'ndc) Vare chosen` of :suclr thickness as to Yholdvalve ,e1-,in thev position shown, registerlling Withthe middleif'acef'o the -pistonbore.

The middle 'face isrjan-*unbrokenring,

closely. iittingva'lve l61.". Each of theother orl extreme faces'has ar'plurality` of slots 'c6 na'nd';,Figures 1 and 3', cut across it to forma ley-passforoilwhenthvalve movesv a tion. The grooves 612 are forfacilitating l It will be understood 'then Vthat 'movement chamber 'tothe. other, soi'long as the; movein a good road, leaving thevehiclesprings free toiiex .In thesesma-ll movements" of'v the pis-'ton' to right r and left, valve e1 moves to left and right. relativeto.the piston,l sliding f in B ut lifi'the" movementis greater than thissmall `amount5 thefrr'esi'st-'aince *tof-,springs e4 y and" 611v becomesatret'arding'iactor. Gonsider' movement'I 'of piston Z -inone"direction, l say to the'jri'ght.' the movementicontinue's, "valve,elsislfo'rced `toA the leftA relative to the "piston, "i IVifhentthe`Amovementrhasgone -ffar pressionichamber through slotsP 'e7-and portsS6513* to' theleftcompression" chamber.

tardingrthe movement of, the piston andhence the''tlexing Aoi'chevehicle spring. i Butthe y'ond a pre'determineddegree).-itfreachc` aelmoves no fartherfagainstfthe-resistanceof spring e4. As'the'n1ovement-of the-piston continues.' q'oiliescapesats'ubst-,anti-al-ly `constant' pressure; *the*1flexing-lief f the f vehicle `springfcan 'continuefbutfwith aoonstantf;not 1 fan,increasing,retardingorce Lees,

spring e9 into action in the same manner, resisting the movement with arapidly increasing force, which reaches a maximum and then retardsfurtherrflexing of the vehicle spring, in the opposite direction, with aconstant retarding force'.

v"Butspring @-1v is seen to be astouter spring than 611, so that Whilethe retarding action is alike yin bothy directions, rapidly building``upA` to af'maXi'mumandthenvcontinuing substantially constantythismaximum is greater inione direction than in the other. The retarding`lforce in either direction may be determined,asdesired7 by a spring ofsuitable strength.

It is Wellknownthat 'changes of temperature cause great va-riations'inthe viscosity'of oil..-' But Avariations in Viscosity of -theI oil cancause only slight changesin the-foperation'ot-this'device-or valveer1-simply opens` alittle Wider when the viscosity increases, theincreased compression of springs ell-fand .ell-` from-this cause beingnegligible.v l

-Atthe top of Veach compression chamber a passage 4b3- leadin'g tochamber y alfy and --controlled by Wall valve 1134:.- ScreW `Z210 limits'theball ^to very slight liftingioff its seat, so thatin the; operation'of .the device only negligible volumes of oil can-pass,.but

any air in the cylinder canquiclrly escape."

4=-"1-`;t=the'bottom ofeach compression chamber is a similar passageallfleadmgI-into -passage' a9 and-controlled by ball valve. @12. #Screwfa1() limitstheball to lslifghtlifting so tlifat=onl-y small volumes ofoil canpass, ibut `theseare `s'uiiicient .to insure that .thecompression chambers shall be always completely fullf ofoil. Oilin-small volui'nesthen. passes the upper ball b4 at each increasel ofpressure in its compression-chamber andpasses thelower ball'alQ atueachfall of pressure.

This slight circulation passes from the compression' chambers throughchamber 1,15l down through reservoir a4, througlrholesl 0114 and"a15and-'passage a9, back to thel compression',r i

chambers. A `fine gauze a8 may! be-soldered over' holes L1-i to arrestany foreign-matter. Plug a7 may bef-unscrewed land-removed forcleaninglthe gauze.

By this means, flexing; of the *vehicle* springs by ordinaryv unevennessof the :road is leftsubstantially unmodified; Vwhile'fcompressiveandrecoil flexingv due to ylarge n- -equ'alitiesin "the road isgreatlyfmodied.

-Coinpressive flexing is retarded'` by rapidly increasing resistance.which reaches a maxi- -m-uni and then continues constant. rBut theresistance tofcompressive flexing may be relaposed; f by a.l rapidlyincreasing:- resista-nce, VWhich reaches a maximumv and. then .continues"constant, "but this. maximum isy much` greater than" with?. the:compressivev flexing. f The :inequ'alitiesiof .thezroa'dfaresmoothedout to a greazter degreejbysrthis improvedzshoclrzabsorber. AnditsV operation remains automatically unchanged by changes of season andtemperature.

While I have described a preferred form of the device, the invention isnot intended to be limited to the form shown and described.

lVhat I claim is l. A hydraulic shock abso-rber comprising a closedcylinder, a hollow piston having one end open, a compression chamber oneach side of the piston, a diaphragm in the piston forming a chamberadjacent its open end, a. conduit through the piston Iconnecting thechamber within the same to the compression chamber remote therefrom,valve mechanism controlling the passage of liquid through the chamberwithin the piston adapted to open on pressure in either direction, andtwo springs, one reacting to restrain the opening of the valve in onedirection and the other reacting to restrain the opening in the otherdirection, so that during a predetermined initial amount of movement ofthe piston from normal position, the valve shall remain closed. Y

2. A hydraulic shock absorber comprising a closed cylinder, a hollowdouble-ended piston therein, a compression chamber on each side of thepiston, means for operably connecting Vthe shocked member to berestrained to the piston, a. diaphragm across the interior of the pistonforming a chamber at one end thereof, an opening through the end of thepiston connecting theV chamber within the same to the adjacentcompression chamber and admittingthe flow of liquidv from one chamber tothe other, conduits through the body of the piston connecting thechamber within the same to the compression chamber remote therefrom andadmitting passage of liquid between such two chambers, a piston valvefitting and slidable in the interior of thechamber within the piston,passage ways adapted to enable fluid to pass from one side to theotherof the piston valve when the valve is moved from normal position,twosprings, one reacting to restrain the piston valve from moving onpressure in one direction and the other reacting torestrain the pistonvalve from moving on pressure in the other direction. p

8. A hydraulic shock absorber comprising a closed cylinder, a hollowdouble-ended piston therein, a compression chamber on each side of thepiston, means for operably connecting the shocked member to berestrained with the piston, a diaphragm across the piston Vforming achamber at one end thereof, an opening through the end of the pistonconnecting the chamber within `the same to the adjacent compressionchamber,

and admitting the passage of fluid from one chamber to the other,conduits through the body of the piston connecting the chamber withinthe same to the compression chamber remote therefrom and admittingpassage of liquid between such two chambers, a part of v the wall of thechamber within the piston thickened on the inner side, such partextending round the circumference andv for a suitable axial length, apiston valve fitting and sliding in such thickened wall part and 1normally .located across` the centre of su-ch part, axial groovesin thethickened-wall part on either sideof the normal location of the j pistonvalve whereby, on movement of the piston valve away from its normalpositionv liquid can pass from one side to the other of the pistonvalve, two springs one re-act-ing to restrain the piston valve frommoving under pressure in lone direction and the otherl reacting-torestrain the piston valve from Y moving under pressurein the 'otherdirection.

4. -A hydraulic shook absorber comprising a closed cylinder, 'a hollowdouble-ended piston therein, a compression chamber Von each side of thepiston, means for operably connecting the shocked7 vmember to berestrained with the piston, adiaphragm4 exf tending-across the pistonforminga chamber at one end thereof, a co-axial cylindrical projectionextended from the` diaphragm into the chamber. within the piston, a holethrough g,

the end of the piston connecting the chamber within the same to theadjacent compresj sion chamber and admitting passage of liquid betweensuch chambers, holes through the body of the pistonconnectingthe spacebetween the cylindrical projection and the wall Y of the chamberwithinthe piston to the compression chamber remotegtherefromandadmitting the passage of liquid between such spaceand compressionchamber, a part of the wall ofthe chamber within the piston thickened`on the inner side, such part extending round the circumference-and fora suitable axial length, a two diameter'` piston valve, theV smallerpart fitting and sliding in the said cylindrical projection and thelarger part fitting and sliding in the thick-l ened wall part andnormally located across the centre thereof a hole through the centre ofthe piston valve, a pin rigidly secured-to the Vcentre of the diaphragmprotruding ing between the diaphragm and the largerv part of'thepistonvalve and the other encircling the pin and reacting betweenv the seatingor washer and the piston valve, radial recesses in thickened wall partextending thewhole length thereof except the part of` the normallocation of the piston valve whereby on movement of the piston in eitherdirection: frolnnormal. position I liquid can passifrom." onesidefto=th`e other o'fr the pistoni.

val-ve.4

52.- Aihydraul'ic shock absorber c0in-prisingVv a-olosedcylinder a1pistom-a compression? chamb'eivo'n` eaehsde of the pistonga passage:connecting the ytwo. compressioni chambers' tl'irough thel piston;valvem'echanism control` ling' `theE passage* opening vonpressure frometherisiele;V elastic meansrestralning the opening offtlie-Valve,areservoir; aconduitf fromithfe bottomof such reservoir to each' ofthecompression chambers',and a one way Valve controllingy eachl of suchconduits.

6".l Alhydra-ulic shock absorber comprising a closed.l cylinder, apston,= a: compression chamber on each side ofthe piston,` a passage I oconnecting' the two 1 compressionA chambers throughi the piston, `valvemechanism controlling' the passage opening on .pressurel fromeitherside,elastic meansrestrainingtheopemng'fof the Valve, and-air leaks per'-mitting the escape of air from the compression chambers:- Y

Y lgroove'sintothree faces; a piston Valve slid- 'HAS hydraulic shockabsorber comprising y a-cylinderl closed at both ends; a hollow pis`tonlintheeyl'inder; a Valve seat formed byy afthickened portion of thepiston wall,-hav ing afn'ished bore broken by two annular ably'fitting;the-l bore; lay-passes' formed by. slots 'acrossthe'V two eXtreme faces;and spring's adapted to hold the piston Valve in`regfisteriwith''th-e3middle face? to close theby' 'pa'SSBSl Inwitness". whereof? I1 haveV signed this' speci-ication.

FREDERICK HENRY ROYCE; Y

